Dyeing textile materials



- objects Patented Nov. 7, 1939 PATENT OFFICE DYEING TEXTILE MATERIALSColver IQDyer, Winchester, Mass, assignor, by

mesne assignments,

Monsanto Chemical Company, a corporation of Delaware No Drawing.Application May 29, 1936, Serial N0. 82,523

7 Claims.

The present invention relates to the dyeing of fibrous materials and ithas particular relation to the dyeing of such materials as wool orleather which are composed of proteinous fibers or filaments.

The main objects of the invention are to provide:

A material for obtaining so-called level" or uniform impregnation of thefibers by the dye.

'A material for producing uniformity of color in union" and speckdyeing. These and other will be apparent from consideration of thefollowing specifications and the appended claims.

In the dyeing of wools, leathers and similar materials containingprotelnous substances as essential constituents of the fibers,difiiculty is experienced by reason of the fact that some dyes do notuniformly penetrate into the fibers and as a result more or lessmottled, streaky, uneven effects are obtained. Such dyes are termed"unlevel". This is especially true in the case of certain cheap dyes,some of which are extremely resistant to fading and discoloration underthe influence of washing, exposure to light, and perspiration, andwhich, if they were leve would have gone onto much wider use than theyhave heretofore enjoyed. In consequence, dyers have been forced toresort to the use of much more expensive materials, some of which werealso characterized by low resistance to fading and discoloration by theabove indicated agencies. It has been proposed to overcome the unleveleffects of the first mentioned class of dyes by conducting dyeingoperations in the presence of certain agents, notably Glaubers salt.While these agents produced some improvement, they were never entirelysatisfactory.

Difiiculty has also been experienced in the dyeing of mixed fabricscomposed of threads or fibers of wool interspersed with threads or bitsof cotton or the like cellulosic materials, because the wool tended toabsorb dye more readily than the cellulosic fibers and as a resultuniform color of the finished product could not be obtained.

The present invention is cased upon the discovery that certain reactionproducts of formaldehyde and sulfonated aromatic compounds, such asnaphthalene, when incorporated into dye solutions have the property ofproducing highly uniform impregnation'of proteinous fibers composingsuch materials as wool, leather or the like and excellent level effectsare obtained even with dye compounds which have heretofore been sounlevel in characteristics as practically iCl. 8-44.)

to inhibit their use at least in the finer grades of materials. Greatuniformity of color is also produced upon textile materials consistingof wool or similar proteinous materials mixed with cotton or similarcellulosic materials. It thus becomes 5 possible to dye mixed fabrics tosubstantially uniform color by application of the foregoing reactionproducts.

Certain condensation products of naphthalene sulfonic acidand-formaldehyde have heretofore'lil been suggested as synthetic tanningagents and are termed syntans. While the compounds preferred in thepractice of the present invention are related to the syntans, they arecharacterized by higher molecular weight and a slower rate of solution(in the undiluted state) in water than the ordinary synthetic tanningagents. They, also, have the power of reducing the rate of. absorptionof dyes from baths by certain materials, notably wooL to a much greaterdegree than the ordinary synthetic tanning agents. These characteristicsconstitute convenient tests for distinguishing applicants preferredmaterial from the'ordinary synthetic tanning agents.

The new dye retarding compounds are readily obtained by condensingsulfonated aromatic compounds such as naphthalene with formaldehyde.Usually the degree of sulfonation should correspond at least to themono-sulfonic acid derivative of the aromatic compound and pref- 3Qerably it should approach that theoretically required fordi-sulfonation. Very satisfactory results are obtained when the suitegroup is combinedin the ratio of approximately 1.6 or 1.? mols per mol.of naphthalene. This may be obtained by heating two parts by weight of100% sulfuric acid with one part of naphthalene at a temperature of 140C. for a period of three hours.- The sulfonatlon of naphthalene andsimilar organic compounds by means of concentrated sulfuric acid orchlor-sulfonic acid is well known to those skilled in the art anddetailed discussion is not deemed to be necessary. The sulfonatednaphthalene when cool is admixed in a closed vessel with 12 liters ofwater per 22 kilos of original naphthalene, and formaldehyde of 37% byweight concentration in a suitable ratio. Ratios of from .47 to about 1part of formaldehyde to 1 part of original naphthalene and even somewhathigher or lower may be used but the ratio of about 1 part of naphthaleneto 0.7 part formaldehyde is deemed to be preferable. The

addition of formaldehyde requires about four hours and the sulfonic acidsolution is maintained during this period at a temperature of about 80C. After all of the formaldehyde has American Association of TextileChemists as been added, the temperature is raised to and 208. shouldalso contain of 28% with the dye levelling compound in appropriateamount (e. g. 20%) based upon the weight or the test wool to be dyed.

amount of material is equivalent to 1.5% of naphthalene upon a likebasis.

The wool sample equals 2.2% by weight of the water in the bath. Thetemperature of the bath is initially about 50 C. It is then brought upto a temperature of 94 C.

one-half hours. A four kilo portion of water 5 is then added andreaction is continued as a final stage for six to twenty hours longer.'lemperature difierences greater than 2 C. in various parts of the bathare to be avoided during the reaction.

15 time and temperature of reaction ingly adjusted. If the amount ofwater is materially reduced, it is desirable to reduce the reactiontemperature in order to slow down the rate of reaction sufllciently toadmit of proper 20 tests for determination oi the degree of reaction.

The following constitutes a suitable test for determination of thesuitability or the material for use in dyeing operations:

Take a sample equivalent to .78 gram of the original naphthalene, whichsample, it the material is foregoing directions, grams. The sample withagitation to 1500 cc. of water having a temperature of 90 C. The timerequired for the material to pass into solution is found to vary withthe degree of reaction of vals and titrated in accordance with standardprocedure with titanium trichloride solution. -The degree of dyefixation 30 Dgle Dyo soln+20% so new condense- Percent dye theorizedtram bath blank tion product It will be noted that with the highlycondensed product constituting the subject matter of the slightly 1955'but Products dissolving Within present invention, the time required toobtain about ten minutes are also satisfactory for many 40% wsommon ofthe d e is more than twice Purposesas great as that required to obtainan equal At the end of the reaction, soda dry degree of ahwrpgion m theblank as a Solution, is added to the hot In the dyeing 0f was! the absvedescribed material may be employed with satisfactory results over a widerange of proportions. As little as 0.3 of 1% will in some cases producenotable levelling efiects and as much as 3G% or even more may in somecases be employed. Probably best results are obtained by employing fromto 20%. These values are based upon the weight of wool contained in thefabrics which are to be treated. The proportion of water into solution65 2:3 to 45 times the The proportion of dye, of course, will dependupon the intensity of the shade desired, the nature of the dye employedso that the levelling action and various other factors as wellunderstood by upon the absorption of dyes is relatively low thoseskilled inthe art. However, if the reaction between the aromaticApplication of the condensation products is sulfonic acid and theformaldehyde is continued not restricted to the particular dye mentionedover too long a period or at too high a term above but may be made tonumerous other dyes 65 perature the material enters into a relatively ofsome of the insoluble stage and is then impracticable for use dyes to wi h p i n f the compounds has in ordinary dyeing operation. een made.The numbers given are those em- An additional test for determination ofthe Suitability f the product for use in dye levelling the AmericanAssociation of Textile Chemists 70 operations, involves determination ofits power and Coloristto slow up the rate of dye absorption by woolen252 79 304 goods. This test may conveniently be conducted 179 1054 670as follows: Prepare a test bath containing 3% 246 53 419 by weight ofSulfone Acid, Blue R designated 114 666 430 75 in the Color Index of1934, published by the 2.078 833 138 dill ilt

iii)

Sulfonated benzene, toluene, xylene, diphenyl and propylated orbutylated benzene, or naphthalene and phenol and alpha or beta naphtholmay be substituted for sulfonated naphthalene and condensed withformaldehyde to provide materials which are also contemplated by thepresent invention. Sulfonation may follow condensation of the aromaticcompound with formaldehyde. Other aldehydic agents than formaldehyde, e.g. hexamethylenetetramine acetaldehyde and furfural may be employed.

The levelling agent may be employed in redyeing operations such as speckdyeing in which a readily dyeable material such as wool, that containssome more difiicultly dyeable fibers such as cellulose, is firstsubjected to the action of an ordinary dye with or without a levellerand is then re-dyed in an additional bath especially suitable .torcoloring the cellulosic fibers. If the latter bath contains thelevelling agent disclosed herein, the cellulose fibers will be dyed toapproximately the same shade as the wool. If the leveller is omitted,the wool will be much more strongly colored than the cotton.

Although only the preferred forms of the invention have been shown anddescribed, it will be apparent to those skilled in the art that theinvention is not limited to these specific forms but numerousmodifications may be made therein without departure from the spirit ofthe invention or the scope of the appended claims.

What I claim is:

i. A dye levelling compound for retarding the fixation of dyes toproteinous materials comprising a reaction product of formaldehyde andnaphthalene sulfonic acid, an unneutralized 3.5 gram sample of which,when it is of such water content as to contain .76 gram of naphthalene,will dissolve in 1,500 cc. of water at 90 C. within a period ofapproximately six to thirty minutes.

2. A method of promoting uniform dye impregnation of woolen textilematerial with acid dyes comprising incorporating into the bath employedin dyeing the material, a condensation product of naphthalene sulfonicacid and formaldehyde, said condensation product being semi-gelatinouswhen admixed with 8.4 parts of water per unit weight of naphthaleneintroduced into the reaction product, and further characterized by theability to retard the fixation of acid dyes to the textile material.

3. A method of promoting level dyeing of proteinous fibers with aciddyes which comprises introducing into the bath employed in the dyeingoperation, a condensation product of naphthalene sulfonic acid andformaldehyde, said condensation product being characterized by theability to reduce the rate of dye-absorption to approximately 85% orless of the normal rate when introduced into a bath of normally unlevelacid dyestuff and further characterized in that said condensationproduct is semi-gelatinous when admixed with 8.4 parts of water per unitweight of naphthalene introduced into the reaction product.

4. A method of promoting uniform dye impregnation of woolen textilematerial with acid dyes, which comprises incorporating into the bathemployed in dyeing the material, a condensation product of naphthalenesulfonic acid containing sulfo groups substantially in excess of monomolar ratio with respect to the naphthalene and formaldehyde, theformaldehyde being in a ratio of from .5 to .7, with respect to thenaphthalene, said product being semi-gelatinous when admixed with 8.4parts of water per unit weight of naphthalene introduced into thereaction product, and

further characterized by the ability to retard the fixation of acid dyesto the textile material.

5.. A method of promoting level dyeing of proteinous fibers with aciddyes which comprises introducing into the bath employed in the dyeingoperation a reaction product of naphthalenesulfonic acid with from .7to-l part by weight of 37% formaldehyde, said product. beingsubstantially free of tanning properties, and further characterized bythe ability to retard the fixation of acid dyes to the fibers and by thefact that an unneutralized 3.5 gram sample thereof when it is of suchwater content as to contain .76 gram of naphthalene will dissolve in1500 cc. of water at 90 C. within a period of approximately 6 to 30minutes.

6. A method of promoting level dyeing of union fabrics with acid dyeswhich comprises introducing into the bath employed in the. dyeingoperation a reaction product of formaldehyde and naphthalene sulfonicacid, an unneutralized 3.5 gram sample of which, when it is of suchwater content as to contain .76 gram of naphthalene, will dissolve in1500 cc. of water at 90 C. within a period of approximately six tothirty minutes.

7. A dye levelling compound comprising a reaction product of naphthalenesulfonic acid with formaldehyde, the formaldehyde being in a ratio ofnot less than .47 part of 37% concentration with respect to thenaphthalene, said condensation product being semi-gelatinous whenadmixed with 8.4 parts of water per unit weight of naphthaleneintroduced into the reaction product.

COLVER P. DYE-R.

